HYDE: EXPERIMENTS ON THE SKATE. 



37 



Curve 5. M/32 KCl, Heart and blood pressure were obtained with 

 Hurthle manometer. For respiratory records the lever was attached to 

 the gill arch. 



'^rxrvxrsj^rvxrvnrvxrxr 



The upper curve heart, and from abscissa to heart blood-pressure 

 record. 



Below the latter respiratory curves, and the time in five seconds. 



Blood pressure remained unchanged, respiratory rate decreased, force 

 unaltered, expiratory phase prolonged. Heart rate from 24 to 22, pro- 

 longed diastole and force unchanged. 



Curve 6. M/8 KCl. Lever attached to the tip of the ventricle and gill 

 arch. 



AAAnAn/V\rWllWl 



Upper, respiratory curve. Lower, heart. Time in five seconds. 



The first part of the upper curve of respiration, taken before injection, 

 registered 36; immediately after, force slightly less, but the rate increased 

 to 42, and in ten minutes was normal again. The first part of the lower 

 heart curve before injecting was 34 per minute. For about twenty 

 minutes it was less (27), with prolonged diastole, then gradually in- 

 creasing during fifteen minutes to normal. Force was unchanged. 



Curve 7. Effect of m/8 KCl. 



Upper, heart and pressure recorded with Hurthle mercury manometer. 



Lower, respiratory records from lever attached to a gill arch. 



Pressure before injecting m/8 KCl 20 mm.; after injecting for two 

 minutes 22 mm., then normal. After injecting the solution, the respira- 

 tion for about twenty seconds decreased in rate with prolonged inspira- 

 tion, then for about one minute increased, and in fifteen minutes was nor- 

 mal. Force was unchanged for twenty to sixty seconds, heart rate de- 

 creased with prolonged diastole, then in five minutes normal; force 

 unchanged. 



